Accurately repeating dial type comparator



July 14, 1953 s. A. FOSTER ACCURATELY REPEATING DIAL TYPE COMPARATOR Filed Jan. 7, 1950 mw w w m llallh IA m i@ I v v L 7 5 ,U 2 2 y, M, n M

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Patented` July 14, 1953 UNITED sTATEs PATENT OFFICE ACCURATELY REPEATING nIAL TYPE 4.

' COMPARATOR Shubel A. Foster, Birmingham, Mich. y Application January 7, 195o, serial No. 137,429

pins, threaded joints, etc., to transmit movement and establish dimension; however, the several devices of the prior art have not proven entirely satisfactory inasmuch as the play, relative position and/or inaccuracy between the parts usually causes a different reading on the micrometer when repeatedly measuring the same article or different articles of the same size. n

YWith the foregoing in view, the primary object of the invention is to provide accurate means for transmitting movement axially from one shaft to another which is capable of non-variable repetition as read on highly sensitive instruments.

An object of the invention is to 'provide a spherical or hemispherical head on one shaft or part and a flat tapered or beveled end on the companion part for abutting the spherical or hemispherical head so that the identical contact is achieved and the identical influence is exerted at every repetition of movement.

Other objects of the invention will become apparent by reference to the following description of an accurately repeating dial micrometer employing the axial joint taken in connection with the accompanying. drawing, in which: n

Fig. l is a side elevational view of` amicrometer employing the inventive joint with portions shown in longitudinal cross-section to better illustrate the parts thereof.

Fig. 2 is a side elevational view ofthe device.

Fig. 3 is a partial view of the device similar to Fig. l showing the parts of the device in altered position; and y Fig. 4 is a partial view of the device similar to Fig. 1 showing the parts of the device in altered position from both Fig. l and Fig. 3.

Referring now to the drawing wherein like numerals refer to like and corresponding parts throughout the several views, the dial micrometerl and joint disclosed therein to illustrate the invention comprises a double ended yoke I0, a block I I having a chamber disposed therein on one end of the yoke I 0, a second block I2 disposed on the other end of the yoke I U opposite to the block I I, a stationary anvil I3 disposed in the block I2, ad-

justing mechanism I4 associated with Lthe blockk I2 for adjustably positioning the stationary anvil I3 relative to the block I 2, a traveling plungerIS having a longitudinal keyway I6 disposed in the chamber of the block I I adapted to travel towardl and away from the stationary anvil I3, agkey I1 in the block II extending into the keyway Il of thek plunger I5`preventing relative rotationr between theplunger I5 and the block Iland per,- mitting limited relative yendwise movement be-` tween the key I'I and-the plunger I5 via the key- Way I6, an arcuate seat I8 in the block II adja-4 cent the key Il, a correspondingly arcuate body yI9 on the key Il seated on the seat ladapted to rock therein to adjust the longitudinalposition` of the key I'I-relative tothe block II for in turn adjustingthe limited relativeendwise movement of the plunger I5 in the block II, bolts 20 sek curing the head I8 in adjusted' position relative tothe block I I, a seat 2| within the chamber of the block II, a spring 22` disposed within the chamber of the *blockl II seated on the seat 2| compressed against the upper end of the plunger I5 permitting the plungerr I5'to travel olf the key I1 against its compression and capable of returning the plungerIS to the key I1, a spherical or hemispherical end 23 on the inner end ofthe plunger I5, a 7collar 24 surrounding the end 23 disposed between the plunger I5 and the spring 22, a dial stem housing 25 disposed within theA chamber of the block II axially aligned with the plunger I5, a fitting 26 securing the dial stemV 25 to the block Il, a spring-pressed dial stem 21 within the housing 25, a flat beveled` or tapered end 28 onr the dial stem 21 contacting` the spherical end v23 ontheplunger I5 for accurately transmitting plunger I5 movement to Vthe dialY stem 21',"`a traveling -anvil 30 on the plunger I5, an adjustable, intermediate anvil 3| on the yoke I0for limiting the depth of insertion ofan object to be measuredwhen inserted between the stationary anvil I3 and the traveling anvil 30 and a nger grip 32 facilitating handling of the device. l l

Relative to 'the relation between the beveled end 28 and the spherical head 23, it can be seenr 23. Relative tothe position of the tapered or beveled end 28 onthe stem 2l again Nany circumferential point is suitable, however, it is preferable to position the tapered or beveled end 28 relative to the stem 21 so that the thrust of the taper against the stem 21 is absorbed by the strongest and least distortable part of the mechanism of the dial gauge 29 so as not to put undue strain on the rack or sector within the gauge `29. In this connection the face of the dial 29 can be positioned to the desires of the user relative to the yoke I0 as indicated in Figs. 1, 3 and 4.

The collar 24 can be formed integral with the plunger I5 or manufactured separately or entirely deleted. However, when formed integral' with the plunger I5, the collar 24 provides additional bearing surface within the chamber of the block II against side thrust on the plunger I5. Due to the fact that the contacting head 23' of the plunger I5 is spherical and the end 28 on the stem 2T is tapered, the identical thrust is transferred from the plunger I5 to the stem 2T with each repeating movement of the traveling -f anvil 30; and, due to the fact that the spherical head 23 is specially hardened, wear between the parts is absorbed by the tapered end 28 whichis easily ground to eliminate imperfection in its surface. A 5 degree bevel on the end 28 has been found suitable, however, a larger or smaller degree bevel may be employed if desired.

The key I'I is disposed in the keyway I6 of the plunger I5 between the end walls thereof and is attached to .the arcuate head I9 rockably positioned on the arcuate seat I8 in the block I I with the bolts 20 adjustably securing the head I9 relative to the seat I8 thereby securing the key I'I in fixed adjustable position. If the bottom bolt 2D, Fig. l, is loosened and the top bolt 20 is tightened, the head I9 will rock on the seat I8 pivoting the key downwardly thereby changing the position travel of the plunger I5 relative to the block II. In this way the plunger I5 can be positioned for relative travel from a denite point which is adjustable via the screws 20, seat I8, and head I9.

The operation of the device can Vbest be explained in conjunction with a specic use such as in employing the inventive dial micrometer to measure the size of main bearings being ground on a crankshaft wherein the operator grinds the bearings to the same dimension and measures each bearing with the inventive dial micrometer during grinding and at the termination of grinding, and, in this regard it can be seen that the .fi

user or operator can set the inventive device employing gauge blocks to the desired measurement and then use the device repeatedly throughout his days work, without the device varying from its set dimension from one measurement to the other.

Although but a single embodiment of the invention-has been shown and described in detail, it is obvious that many changes may be made in the size, shape, detail and arrangements of the elements of the invention within the scope of-the appended claims.

I claim:

1. In an instrument for measuring and indicating minute distances, a yoke having a plungerV chamber in one end thereof, a stationary anvil on said yoke oppositely disposed to and axially aligned with the plunger chamber of said yoke, a seat on said yoke within the chamber, a plunger having a keyway endwise movably disposed in the chamber of said yoke below said seat, a traveling anvil on said plunger oppositely disposed to said stationary anvil, a hemispherical interior end on said plunger, a collar on said plunger surrounding said hemispherical end, a spring dis- 4 posed under compression between said yoke chamber seat and said plunger collar, a key extending from said yoke into the keyway of said plunger providing a stop for said plunger against said spring; said plunger being capable of travel against said spring; a dial gauge mounting on said yoke at the plunger chamber and axially aligned therewith, a dial gauge set in said mounting, a stem extending from said dialgauge into the plunger chamber of said yoke, and a 5 degree at beveled end on said stem contacting said `hemispherical end on said plunger whereby movement ofsaid traveling anvil is transmitted to said dial gauge via said plunger and said stem with said hemispherical end of said plunger and said flat tapered 5 degree beveled end on said stem providing I non-varying transmission of movement from said traveling anvil to said dial gauge each time the same measurement is made.

2. An accurately repeating micrometer comprising a double ended yoke, a block havingV a chamber disposed on one end of said yoke, a sec-A ond block disposed on the other end of said yoke opposite ,to said block, a stationary anvil adjustably disposed in said second block, a traveling plunger disposed in the chamber of said block adapted to travel toward and away from said stationary anvil, a spring seated within the chamber of said block compressed against the end of said plunger permitting said plunger to travel against its compression andy capable of returning said plunger, a hemispherical inner end on said plunger, a gauge stem housing disposed within the chamber of said block axially aligned with said plunger, a tting securing said gauge stem housing to said block, a spring-pressed gauge stem Within said housing, a at 5 degree beveled end on said gauge stern contacting said hemispherical end on said plunger for accurately transmitting i plunger movement to said gauge stem, and va gauge on said gauge stem visually indicating movement of said gauge stem.

3. An accurately repeating micrometer comprising a double ended yoke, a block having a chamber disposed on one end of said yoke, a second block disposed on the other end of said yoke opposite to said block, a stationary anvil adjustably disposed in said second block, a traveling plunger having alongitudinal keyway disposed in the chamber of said block adapted to travel toward and away from said stationary anvil, a key in said block extending into the keyway of said plunger preventing relative rotation between said plunger and said block and permitting limited relative endwise movement therebetween, a springsealed Within the chamber of said block compressed against the end of said plunger permitting said plunger to travel off said key against its compression and capable of returning said plunger to said key, a hemispherical inner` end on said plunger, a gauge stem housing disposed within the chamber of said block axially aligned with said plunger, a tting securing said gauge stem housing to said block, a spring pressed gauge stem within said housing, a iiat 5 degree beveled end on said gauge stem contacting said hemispherical end on said plunger for accurately transmitting plunger movement to said gauge stem, and a gauge on said gauge stem visually indicating movement of said gauge stem.

4. An accurately repeating micrometer comprising a double ended yoke, a block having a chamber disposed on one end of said yoke, a second'block disposed on the other end of said yoke opposite to said block, a stationary anvil adjustably disposed in said second block, a traveling plunger having a longitudinal keyway disposed in the chamber of said block adapted to travel toward and away from said stationary anvil, a key in said block extending into the keyway of said plunger preventing relative rotation between said plunger and said block and permitting limited relative endwise movement therebetween, a spring seated within the chamber of said block compressed against the end of said plunger permitting said plunger to travel off said key against its compression and capable of returning said plunger to said key, a hemispherical inner end on said plunger, a gauge stem housing disposed within the chamber of said block axially aligned with said plunger, a litting securing said gauge stem housing to said block, a spring pressed gauge stem within said housing, a flat 5 degree beveled end on said gauge stem contacting said hemispherical end on said plunger for accurately transmitting plunger movement to said gauge stem, a gauge on said gauge stem visually indicating movement of said gauge stem, and an intermediate anvil on said yoke for limiting the depth of insertion of anY object to be measured when inserted between said stationary anvil and said traveling anvil.

5. An accurately repeating micrometer comprising a double ended yoke, a block having a chamber disposed on one end of said yoke, a second block disposed on the other end of said yoke opposite to said block, a stationary anvil adjustably disposed in said second block, a traveling plunger having a longitudinal keyway disposed in the chamber of said block adapted to travel toward and away from said stationary anvil, Va key in said block extending into the keyway of said plunger preventing relative rotation between said plunger and said block and permitting limited relative endwise movement therebetween, a spring seated within the chamber of said block compressed against the end of said plunger permitting said plunger to travel off said key against its compression and capable of returning said plunger to said key, a hemispherical inner end on said plunger, a collar surrounding said hemispherical end disposed between said plunger and said spring, a gauge stem housing disposed within the chamber of said block axially aligned with said plunger, a tting securing said gauge stem housing to said block, a spring pressed gauge stem within said housing, a ilat 5 degree beveled end on said gauge stem contacting said hemispherical end on said plunger for accurately transmitting plunger movement to said gauge stem, and an intermediate anvil on said yoke for limiting the depth of insertion of an object to be measured when inserted between said stationary anvil and said traveling anvil.

6. An accurately repeating micrometer comprising a double ended yoke, a block having a chamber disposed on one end of said yoke, a second block disposed on the other end of said yoke 'opposite to said block, a stationary anvil adjustably disposed lin said second block, a traveling plunger` having a longitudinal keyway disposed in the chamber of said block adapted to travel to,- ward and away from said stationary anvil, a key in said block extending into the keyway of said plunger preventing relative rotation between said plunger and said block and permitting limited relative endwise movement therebetween, an arcuate seat on said block, a correspondingly arcuate body on said key seated on said seat adapted to rock therein to adjust the longitudinal position of said key relative to said block for in vturn adjusting the limited relative endwise movement of said plunger in said block means securing said key-body in adjusted position, a spring seated within the chamber of said block compressed against the end of said plunger permitting said plunger to travel ofi said key against its compression and capable of returning said plunger to said key, a hemispherical inner end on said plunger, a collar surrounding said hemispherical end disposed between said plunger and said spring, a gauge stem housing disposed within the chamber of said block axially aligned with said plunger, a tting securing said gauge stem housing to said block, a spring pressed gauge stem within said housing, a flat 5 degree beveled end on said gauge stem contacting said hemispherical end on said plunger for accurately transmitting plunger movement to said gauge stem, a gauge on said gauge stem visually indicating movement of said gauge stem, and an intermediateanvil on said yoke for limiting the depth of insertion of an object to be measured when inserted between said stationary anvil and saidtraveling anvil.

SHUBEL A. FOSTER.

References Cited in the le of this patent UNITED STATES PATENTS l Switzerland Aug. 1, 1949 

